CN118028463A

CN118028463A - Use of CD36 to identify cancer subjects for treatment

Info

Publication number: CN118028463A
Application number: CN202410057921.5A
Authority: CN
Inventors: 伦道夫·S·瓦特尼克
Original assignee: Childrens Medical Center Corp
Current assignee: Childrens Medical Center Corp
Priority date: 2013-03-14
Filing date: 2014-03-13
Publication date: 2024-05-14
Also published as: ES2872403T3; JP6457999B2; US9921224B2; CN118028464A; EP3919070B1; EP2971166B1; US20180088122A1; WO2014151840A1; JP2016521349A; JP7568400B2; CN105358708B; EP2971166A4; CN105358708A; EP3919070A1; US20180372749A1; EP2971166A1; US20200225240A1; JP2023022019A; JP2018196378A; JP2020073899A

Abstract

The present application relates to the use of CD36 to identify cancer subjects for treatment. Provided herein are methods for identifying a subject having cancer for treatment with a Psap peptide. The subject is identified based on CD36 levels. Also provided herein are compositions and methods for treating a subject having cancer based on CD36 levels.

Description

Use of CD36 to identify cancer subjects for treatment

The application is a divisional application of a Chinese patent application with the application date of 2014, 3-13, the application number of 201480014414.8 and the name of CD36 for identifying a cancer object for treatment, and the original application is a China national stage application of International application PCT/US 2014/026546.

Cross Reference to Related Applications

The present application claims the benefit of the filing date of U.S. provisional application No.61/782,850 filed on day 14 of 3.2013, the entire contents of which are incorporated herein by reference.

Federally sponsored research and development

The present invention was completed with U.S. government support under R01CA135417 awarded by the national cancer institute. The united states government has certain rights in this invention.

Technical Field

The present invention relates to the use of CD36 to identify cancer subjects for treatment.

Background

Cancer remains a major public health primary problem. For example, 760 million people are estimated to die of cancer in 2008. Treatment for cancer continues to improve with advances in technology and science. Unfortunately, it is clear that many cancer therapies are effective only on a subset of cancer patients, even on a subset of patients with the same type of cancer. Thus, it is becoming increasingly important to find ways to identify patients who are likely to respond to treatment.

Disclosure of Invention

Some aspects of the disclosure are based in part on the following findings: elevated CD36 levels in tumor cells indicate that the patient is or is likely to be responsive to Psap peptide treatment. Accordingly, some aspects of the present disclosure relate to methods of assessing responsiveness of a patient to treatment with a Psap peptide by determining CD36 levels in a sample (e.g., a tumor sample). In some embodiments, the methods described herein relate to identifying or selecting patients for treatment with a Psap peptide based on CD36 levels in a sample. Further aspects of the present disclosure relate to compositions and methods for treating a subject with cancer, the subject characterized by elevated CD36 levels.

In some aspects, the disclosure relates to methods for assessing responsiveness of a subject to treatment with a Psap peptide, the methods comprising determining CD36 levels in a sample obtained from a subject having cancer, wherein an elevated CD36 level in the sample as compared to a control level indicates that the subject is or is likely to be responsive to treatment with the Psap peptide. In some embodiments, the level of CD36 in the sample is determined by performing an assay. In some embodiments, the method further comprises identifying a subject having an elevated level of CD36 in the sample as responsive or likely responsive to the treatment with the Psap peptide as compared to a control level. In some embodiments, the method further comprises administering an effective amount of a Psap peptide to a subject identified as responsive or likely responsive to treatment with the Psap peptide to treat the cancer.

Further aspects of the disclosure relate to methods of treating a subject having cancer, the methods comprising administering to a subject having cancer an effective amount of a Psap peptide to treat the cancer, the subject characterized by an elevated CD36 level in the sample as compared to a control level sample. In some embodiments, the control level is a level of CD36 in a non-cancerous cell or tissue obtained from the subject having cancer. In some embodiments, the control level is a level of CD36 in a cell or tissue obtained from a healthy subject or population of healthy subjects. In some embodiments, the control level is a predetermined level. In some embodiments, the CD36 level is a CD36 protein level.

Further aspects of the disclosure relate to a method for treating a subject having cancer, the method comprising: (a) Selecting a subject with cancer based on the known subject having an elevated level of CD36 in the sample as compared to a control level; and (b) administering to the subject an effective amount of a Psap peptide because the subject has an elevated level of CD36 in the sample as compared to a control level. In some embodiments, the control level is a level of CD36 in a non-cancerous cell or tissue obtained from the subject having cancer. In some embodiments, the control level is a CD36 level in a cell or tissue obtained from a healthy subject or population of healthy subjects. In some embodiments, the control level is a predetermined level. In some embodiments, the CD36 level is a CD36 protein level.

In some embodiments of any of the methods provided herein, the cancer is prostate cancer, breast cancer, ovarian cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma.

In some embodiments of any of the methods provided herein, the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2), or DWLP (SEQ ID NO: 3), or an amino acid substitution variant thereof, wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

b) An amino acid selected from valine (V), alanine (a) or glycine (G) or a non-standard amino acid of similar size (non-canonical amino acid) or a derivative thereof, in place of leucine (L);

c) Arginine (R) replaces lysine (K);

d) The D-isomer of aspartic acid (D) replaces the L-isomer of aspartic acid (D) and/or the D-isomer of leucine (L) replaces the L-isomer of leucine (L);

e) The D-isomer of tryptophan (W) replaces the L-isomer of tryptophan (W) and/or the D-isomer of proline (P) replaces the L-isomer of proline (P); or a combination thereof. In some embodiments, the Psap peptide is 50 amino acids or less in length. In some embodiments, the Psap peptide is 30 amino acids or less in length. In some embodiments, the Psap peptide is 15 amino acids or less in length. In some embodiments, the Psap peptide is 6 amino acids or less in length. In some embodiments, the Psap peptide is a cyclic peptide. In some embodiments, the similarly sized non-standard amino acid is methylvaline, methylleucine, or sarcosine.

In another aspect, the present disclosure relates to a composition for treating a subject having cancer, the subject characterized by elevated CD36 levels in a sample as compared to a control level, the composition comprising a Psap peptide.

In another aspect, the present disclosure relates to the use of a composition comprising a Psap peptide in the manufacture of a medicament for treating a subject having cancer, the subject characterized by an elevated CD36 level in a sample as compared to a control level.

In some embodiments of the uses or compositions provided herein, the control level is a level of CD36 in a non-cancerous cell or tissue obtained from the subject having cancer. In some embodiments of the uses or compositions provided herein, the control level is a level of CD36 in a cell or tissue obtained from a healthy subject or population of healthy subjects. In some embodiments of the uses or compositions provided herein, the control level is a predetermined level. In some embodiments of the uses or compositions provided herein, the CD36 level is a CD36 protein level.

In some embodiments of the uses or compositions described herein, the cancer is prostate cancer, breast cancer, ovarian cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma.

In some embodiments of the uses or compositions described herein, the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2), or DWLP (SEQ ID NO: 3), or an amino acid substitution variant thereof, wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

b) An amino acid selected from valine (V), alanine (a) or glycine (G) or a non-standard amino acid of similar size or a derivative thereof;

c) Arginine (R) replaces lysine (K);

In some embodiments of the methods, compositions or uses provided herein, the sample is a tumor sample.

Drawings

FIG. 1A is a graph showing proliferation of LLC cells 48 hours after addition of serial dilutions of recombinant Tsp-1 or DWLPK (SEQ ID NO: 2) peptide.

FIG. 1B is a photograph of a western blot showing expression of CD36 protein in LLC cells.

FIG. 2 is a photograph of a western blot showing expression of CD36 protein in breast cancer (MDA-231, MCF-7), ovarian cancer (ID 8), melanoma (B16), prostate cancer (PC 3 and LNCaP) and Lung Cancer (LLC) cell lines.

FIG. 3 is a photograph of a western blot showing expression of CD36 protein in primary ovarian cancer cells (primary ovarian CANCER CELL) from ascites in a patient.

FIG. 4 is a photograph of a western blot showing expression of CD36 protein in pancreatic (AsPC 1), ovarian (DF-14 and ID-8), breast (MDA-MB 231 and LM 2), prostate (PC 3, PC3-M-LN4, LN-CAP and LN-CAP-LN 3), melanoma (B16-B16) and lung cancer (LLC) cells. Exemplary high and low CD36 expressing cell lines are shown in the box.

FIG. 5 is a graph showing that dW1P (SEQ ID NO: 47) peptide causes cancer regression in a cancer model expressing high levels of CD 36.

FIG. 6 is a graph showing that ovarian cancer cells expressing CD36 are susceptible to Tsp-1 mediated cell killing.

FIG. 7 is a graph showing primary tumor mass of mice injected with AsPC pancreatic cancer cells expressing high levels of CD36 and then treated with dW1P (SEQ ID NO: 47) peptide or control. Primary tumor mass was inhibited by peptide treatment.

FIG. 8 is a graph showing that treatment of mice with dW1P (SEQ ID NO: 47) peptide with B16-B16 melanoma, which expresses low levels of CD36, inhibited tumor growth, but did not regress the tumor.

Detailed Description

The Psap peptide is a therapeutic peptide containing the amino acid sequence of a fragment originally derived from Saposin A (a known anti-angiogenic protein). Psap generally comprises the core sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3) or amino acid substitution variants thereof, and may be as little as 4 amino acids long (e.g., a peptide consisting of DWLP (SEQ ID NO: 3) or amino acid substitution variants thereof). Such Psap peptides have been previously shown to be effective in treating various types of cancers (see, e.g., PCT publications WO2009002931 and WO/2011/084685; PCT application PCT/US2012/71424, published as PCT publication WO/2013/096868, and U.S. patent applications 12/640,788 and 13/516,511, all of which are incorporated herein by reference in their entirety). It was previously thought that administration of the Psap peptide stimulated thrombospondin (Tsp-1) in vivo, which in turn acted on endothelial cells, causing an anti-angiogenic effect resulting in indirect inhibition of cancer and/or metastatic growth.

As described herein, tumor cells from a variety of different types of cancers that respond to Psap peptides have been found to express CD36.CD36 is a member of the class B scavenger receptor (SCAVENGER RECEPTOR) family of cell surface proteins and has many ligands, including oxidized low density lipoproteins, oxidized phospholipids, long chain fatty acids, collagen, and Tsp-1. Without wishing to be bound by any theory or mechanism, it is believed that administration of the Psap peptide stimulates Tsp-1, which then acts directly on the tumor cells by interacting with CD36 on the tumor cells. Interactions between Tsp-1 and CD36 on tumor cells can lead to inhibition of tumor proliferation and/or induction of tumor cell apoptosis. Thus, the Psap peptide appears to treat cancer by two different independent mechanisms, indirectly through anti-angiogenic effects and directly through Tsp-1 interactions with CD36 on tumor cells. Thus, responsiveness of a subject with cancer to treatment with a Psap peptide may depend on the level of CD36 expressed by the cancer.

Accordingly, some aspects of the present disclosure relate to methods for assessing responsiveness of a subject to treatment with a Psap peptide by determining CD36 levels in a sample (e.g., a tumor sample). In some embodiments, the methods described herein relate to identifying or selecting a subject for treatment with a Psap peptide based on CD36 levels in a sample (e.g., a tumor sample). Further aspects of the disclosure relate to compositions and methods for treating a subject with cancer, the subject characterized by elevated CD36 levels (e.g., selected or identified based on the cancer having elevated CD36 levels in a sample as compared to control levels).

As used herein, "responsive to treatment with a Psap peptide" includes, but is not limited to, preventing or reducing the occurrence of cancer, reducing symptoms of cancer, suppressing or inhibiting the growth of cancer, preventing metastasis and/or invasion of existing cancer, promoting or inducing regression of cancer, inhibiting or suppressing proliferation of cancer cells, reducing angiogenesis, and/or increasing the amount of apoptotic cancer cells in response to treatment with a Psap peptide.

As used herein, "non-responsive to a Psap peptide treatment" includes, but is not limited to, failing to prevent or reduce the occurrence of cancer, failing to reduce symptoms of cancer, failing to suppress or inhibit the growth of cancer, failing to prevent metastasis and/or invasion of existing cancer, failing to promote or induce regression of cancer, failing to inhibit or suppress proliferation of cancer cells, decreasing the amount of apoptotic cancer cells, and/or failing to reduce angiogenesis in response to a Psap peptide treatment.

Diagnostic and theranostic (theranostic) methods

Aspects of the present disclosure relate to diagnostic and theranostic methods useful for assessing responsiveness of a subject to treatment with a Psap peptide. In some embodiments, the method comprises determining the level of CD36 in a sample obtained from a subject having cancer, wherein an elevated level of CD36 in the sample compared to a control level indicates that the subject is or is likely to be responsive to the Psap peptide treatment (i.e., if the level of CD36 in the sample is elevated compared to the control level, the subject is identified as being or is likely to be responsive to the Psap peptide treatment). In some embodiments, the method further comprises identifying a subject having an elevated level of CD36 in the sample as responsive or likely responsive to the Psap peptide treatment as compared to a control level. In some embodiments, the methods further comprise administering to a subject identified as responsive or likely responsive to treatment with a Psap peptide an effective amount of a Psap peptide described herein to treat cancer. In some embodiments, the sample obtained from a subject having cancer is a tumor sample.

In some embodiments, an elevated level of CD36 in the sample as compared to a control level indicates that the cancer will resolve or is likely to resolve in response to the Psap peptide treatment. In some embodiments, the method further comprises identifying a subject having an elevated level of CD36 in the sample as having a cancer that will resolve or likely resolve in response to treatment with the Psap peptide as compared to a control level. In some embodiments, the method further comprises administering to a subject identified as having a cancer that will regress or likely regress in response to treatment with a Psap peptide, an effective amount of a Psap peptide described herein to cause regressions of the cancer.

As used herein, "elevated CD36 level" means that the CD36 level is above a control level, e.g., above a predetermined threshold or CD36 level in a control sample. Control levels are described in detail herein. Elevated CD36 levels include, for example, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 150%, 200%, 300%, 400%, 500% or more CD36 levels higher than the control level. Elevated CD36 levels also include an increase in the phenomenon from a zero state (e.g., no or undetectable CD36 expression in a control) to a non-zero state (e.g., some CD36 expression or detectable CD36 expression in a sample).

As used herein, "treatment with a Psap peptide" is intended to include administration of the Psap peptide to a subject. Psap peptides are described herein. It will be appreciated that treatment with the Psap peptide may include treatment with the Psap peptide alone or may include treatment with a variety of agents or therapies, such as the Psap peptide and additional chemotherapeutic agents and/or additional forms of therapy, such as surgery, radiation therapy or chemotherapy.

Treatment of

Further aspects of the disclosure relate to methods of treating a subject having cancer. In some embodiments, the method comprises administering to a subject having cancer an effective amount of a Psap peptide described herein to treat cancer, the subject characterized by an elevated level of CD36 in a sample obtained from the subject as compared to a control level. In some embodiments, the method comprises:

(a) Selecting a subject with cancer based on the known subject having an elevated level of CD36 in the sample as compared to a control level; and

(B) Because the patient has an elevated level of CD36 in the sample as compared to the control level, an effective amount of the Psap peptide is administered to the subject.

Further aspects of the disclosure relate to compositions and use of the compositions in the manufacture of a medicament for treating a subject having cancer, the subject characterized by having elevated CD36 levels in a sample. In some embodiments, the composition comprises a Psap peptide described herein. In some embodiments, the sample is a tumor sample.

As used herein, "treatment" includes, but is not limited to, preventing or reducing the occurrence of cancer, reducing symptoms of cancer, suppressing or inhibiting the growth of cancer, preventing metastasis and/or invasion of existing cancer, promoting or inducing regression of cancer, inhibiting or suppressing proliferation of cancer cells, reducing angiogenesis, and/or increasing the amount of apoptotic cancer cells. In some embodiments, the treatment of cancer directly inhibits or suppresses proliferation of cancer cells, and does not involve inhibition or suppression of angiogenesis (with grounding resulting in inhibition or suppression of proliferation of cancer cells).

An effective amount is a dose of the Psap peptide sufficient to provide a medically desirable outcome (e.g., treatment of cancer). The effective amount will vary with the particular cancer being treated, the age and physical condition of the subject being treated, the severity of the condition, the duration of the treatment, the nature of any concurrent therapy (concurrent therapy), the knowledge of the healthcare practitioner and factors within the expertise of the particular route of administration, and the like. For administration to a subject (e.g., a human), a dose of about 0.001, 0.01, 0.1, or 1mg/kg to 50, 100, 150, or 500mg/kg or more may be generally used.

The Psap peptides and compositions thereof may be formulated for a variety of modes of administration, including systemic, topical, or topical (localized) administration. Techniques and formulations are generally found in Remington' sPharmaceutical Sciences, mack Publishing co., easton, pa., latest edition. When administered, the Psap peptide may be employed in pharmaceutically acceptable amounts and in pharmaceutically acceptable compositions. Such formulations may conveniently comprise salts, buffers, preservatives, compatible carriers and optionally other therapeutic agents. When used in medicine, the salts should be pharmaceutically acceptable, but non-pharmaceutically acceptable salts may be conveniently used to prepare pharmaceutically acceptable salts thereof and are not excluded from the scope of the present disclosure. Such pharmacologically useful or pharmaceutically acceptable salts include, but are not limited to, those prepared from the following acids: hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, maleic acid, acetic acid, salicylic acid, citric acid, formic acid, malonic acid, succinic acid, and the like. Alternatively, the pharmaceutically acceptable salts may be prepared as alkali or alkaline earth metal salts, such as sodium, potassium or calcium salts.

The Psap peptide may optionally be combined with a pharmaceutically acceptable carrier. The term "pharmaceutically acceptable carrier" as used herein means one or more compatible solid or liquid fillers, diluents or encapsulating substances suitable for administration to a human. The term "carrier" means a natural or synthetic organic or inorganic ingredient in combination with an active ingredient to facilitate application. The components of the pharmaceutical composition can also be blended with the molecules of the present disclosure and interact with each other in a manner that does not significantly impair the desired efficacy of the drug. Some examples of substances that may serve as pharmaceutically acceptable carriers include: (1) sugars such as lactose, glucose, and sucrose; (2) starches, such as corn starch and potato flakes; (3) Cellulose and its derivatives, such as sodium carboxymethyl cellulose, methyl cellulose, ethyl cellulose, microcrystalline cellulose, and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) Lubricants, such as magnesium stearate, sodium lauryl sulfate, and talc; (8) excipients such as cocoa butter and suppository waxes; (9) Oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; (10) glycols, such as propylene glycol; (11) Polyols such as glycerol, sorbitol, mannitol and polyethylene glycol (PEG); (12) esters such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethanol; (20) a pH buffer solution; (21) polyesters, polycarbonates and/or polyanhydrides; (22) bulking agents, such as polypeptides and amino acids; (23) serum components such as serum albumin, HDL and LDL; (22) a C2-C12 alcohol, such as ethanol; and (23) other non-toxic compatible substances for use in pharmaceutical formulations. Humectants, colorants, release agents, coating agents, sweeteners, flavoring agents, fragrances, preservatives and antioxidants may also be present in the formulations.

The pharmaceutical composition may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. When used in reference to the pharmaceutical compositions of the present disclosure, the term "unit dose" refers to physically discrete units suitable as unitary dosages for subjects, each unit containing a calculated predetermined quantity of active material in association with the required diluent (i.e., carrier or vehicle) to produce the desired therapeutic effect.

A variety of routes of administration may be utilized. The particular mode selected will be selected according to the type of cancer being treated and the dosage required for the therapeutic effect. In general, the methods of the present disclosure can be practiced using any medically useful mode of administration, meaning that any mode that produces an effective level of the active compound without causing clinically unacceptable adverse effects can be used. Such modes of administration include oral, rectal, topical, nasal, intradermal (interdermal) or parenteral routes. The term "parenteral" includes subcutaneous, intravenous, intramuscular, or infusion.

In some embodiments, the administration is parenteral. Injectable formulations suitable for parenteral administration include, for example, sterile injectable aqueous or oleaginous suspensions and may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3 propanediol or 1,3 butanediol. Among the carriers and solvents that can be used are water, ringer's solution, u.s.p. And isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono-or diglycerides. In addition, fatty acids (such as oleic acid) find use in the preparation of injectables. The injectable formulation may be sterile, for example, by filtration through a bacterial-retaining filter, or by incorporating a sterilizing agent in the form of a sterile solid composition which may be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.

For topical administration, the pharmaceutical compositions may be formulated as ointments, salves, gels, or creams, as is generally known in the art. Topical administration may utilize transdermal delivery systems well known in the art. One example is a skin patch. Alternatively, biolistic gene gun delivery methods may be used. Gene guns are devices for injecting genetic information into cells, and are typically designed for plant transformation. Payload is the basic particle of heavy metals coated with plasmid DNA. This technique is commonly referred to simply as biolistic. Another instrument using biolistic technology is the PDS-1000/He particle delivery system. The compositions described herein may also be coated onto tiny gold particles, and these coated particles are "shot" into biological tissue, such as hemangiomas and melanomas, under high pressure. An example of a gene gun-based approach is described by Loehr B.I. et al, J.Virol.2000,74:6077-86 for DNA-based bovine vaccination.

The pharmaceutical compositions described herein are also suitable for administration by intratumoral, intralesional or intralesional routes to exert local and systemic effects. Intraperitoneal routes are expected to be particularly useful, for example, in the treatment of ovarian tumors. For these uses, additional conventional pharmaceutical formulations, such as tablets, granules, powders, capsules and sprays, may be preferred. In such formulations, further conventional additives may also be required, such as binders, wetting agents, propellants, lubricants and stabilizers.

Compositions suitable for oral administration may be presented as discrete units (e.g., capsules, tablets, lozenges) each containing a predetermined amount of the anti-inflammatory agent. Other compositions include suspensions in aqueous or non-aqueous liquids, such as syrups, elixirs or emulsions.

Other delivery systems may include time release, delayed release, or sustained release delivery systems. Such a system may avoid repeated administration of anti-inflammatory agents, increasing the convenience of the subject and the physician. Many types of release delivery systems are available and known to those of ordinary skill in the art. It includes polymer-based systems such as poly (lactide-glycolide), copolyoxalates, polycaprolactone, polyesteramides, polyorthoesters, polyhydroxybutyric acid, and polyanhydrides. Microcapsules containing the foregoing polymers of the drug are described, for example, in U.S. Pat. No. 5,075,109. The delivery system also includes non-polymeric systems that are: lipids, including sterols, such as cholesterol, cholesterol esters, and fatty acids or neutral fats, such as mono-, di-, and tri-glycerides; a hydrogel release system; sylastic systems; a peptide-based system; a wax coating; compressed tablets using conventional binders and excipients; partially fused implants, and the like. Specific examples include, but are not limited to: (a) An erosion system in which an anti-inflammatory agent is contained in a matrix in a form such as those described in U.S. Pat. nos. 4,452,775, 4,667,014, 4,748,034 and 5,239,660, and (b) a diffusion system in which the active ingredient permeates from the polymer at a controlled rate, such as described in U.S. Pat. nos. 3,832,253 and 3,854,480. In addition, pump-based hardware delivery systems may be used, some of which are suitable for implantation.

The use of long-term sustained release implants may be particularly suitable for the treatment of chronic conditions. As used herein, long term release means that the implant is constructed and arranged to deliver therapeutic levels of the active ingredient for at least 30 days, preferably 60 days. Long-term sustained release implants are well known to those of ordinary skill in the art and include some of the release systems described above.

In some embodiments, the pharmaceutical composition for therapeutic administration must be sterile. Filtration through sterile filtration membranes (e.g., 0.2 micron membranes) is easy to achieve sterility. Or preservatives may be used to prevent the growth or action of microorganisms. A variety of preservatives are well known, including, for example, phenol and ascorbic acid. The active ingredient and/or pharmaceutical composition is typically stored in lyophilized form or in aqueous solution if it is highly stable to thermal and oxidative denaturation. The pH of the formulation is typically about 6 to 8, but higher or lower pH values may be suitable in some cases.

In some embodiments, administration of the Psap peptide may be combined with additional therapies, such as chemotherapy, radiation, and/or surgery.

CD36

CD36 (cluster of differentiation 36) is an integral membrane protein found on the surface of many cell types in vertebrates, also known as FAT, GP4, GP3B, GPIV, CHDS, PASIV, SCARB3 and BDPLT10. Entrez Gene ID for human CD36 is 948. Exemplary human CD36 transcripts and proteins are as follows:

CD36 transcript variant 1

CD36 transcript variant 2

CD36 transcript variant 3

CD36 transcript variant 4

CD36 transcript variant 5

CD36 protein

Psap peptides

The pro-sphingolipid activator protein (Prosaposin, psap) is a precursor protein of the sphingolipid activator protein (Saposin) comprising a 16 amino acid signal peptide consisting of about 524-527 amino acids. Full length precursor polypeptides undergo cotranslational glycosylation and modification in the endoplasmic reticulum and golgi system to produce a precursor protein of 70-72 kDa. After transport to lysosomes, cathepsin D participates in its proteolytic process to produce an intermediate molecular form of 35 to 53kDa, then a 13-kDa glycoprotein, and finally into a mature 8-11kDa partially glycosylated form of individual sphingolipid activator molecules (O' Brien J.S., and Kishimoto Y, the FASEB J.,5:301-8,1991;Kishimoto Y, et al, J.Lipid Res.33:1255-67, 1992). The sphingolipid-activated protein was processed into 4 cleavage products: sphingolipid activating protein A, sphingolipid activating protein B, sphingolipid activating protein C and sphingolipid activating protein D. The amino acid sequences of the Psap prepro isoforms A, B and C and the amino acid sequence of the cleavage product, sphingolipid activating protein a, are as follows:

Psap proprotein isoform A

Psap preproprotein isoform B

Psap preproprotein isoform C

Sphingolipid activating protein A

Some aspects of the disclosure relate to Psap peptides and uses thereof. The Psap peptide comprises a sequence originally derived from a fragment of sphingolipid activating protein a. Fragments of sphingolipid activating protein a consisting of as few as 4 amino acids and variants of these fragments have been previously shown to have anti-angiogenic and anti-cancer activity. The Psap peptides and methods of making the Psap peptides are known in the art (see, e.g., PCT publications WO2009002931 and WO/2011/084685; PCT application PCT/US2012/71424, which is published as PCT publication WO/2013/096868, and U.S. patent applications 12/640,788 and 13/516,511, which are all incorporated herein by reference in their entirety).

In some embodiments, the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2), or DWLP (SEQ ID NO: 3), or an amino acid substitution variant thereof, wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

c) Arginine (R) replaces lysine (K);

e) The D-isomer of tryptophan (W) replaces the L-isomer of tryptophan (W) and/or the D-isomer of proline (P) replaces the L-isomer of proline (P); or a combination thereof. In some embodiments, the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2), or DWLP (SEQ ID NO: 3).

It should be understood that the Psap peptide may be of any length. In some embodiments, the Psap peptide is 4、5、6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30、31、32、33、33、34、35、36、37、38、39、40、45、50、55、60、65、70、75、80、85、90、95 or 100 or more amino acids in length. In some embodiments, the Psap peptide is 5、6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30、31、32、33、33、34、35、36、37、38、39、40、45、50、55、60、65、70、75、80、85、90、95、100、200、300、400、500 or fewer amino acids in length. In some embodiments, the Psap peptide is 4-500、4-400、4-300、4-200、4-100、4-90、4-80、4-70、4-60、4-50、4-40、4-30、4-25、4-20、5-500、5-400、5-300、5-200、5-100、5-90、5-80、5-70、5-60、5-50、5-40、5-30、5-25、5-20、6-500、6-400、6-300、6-200、6-100、6-90、6-80、6-70、6-60、6-50、6-40、6-30、6-25 or 6-20 amino acids in length.

It will be appreciated that the amino acids flanking CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3) may be naturally flanking amino acids present in either sphingolipid activating protein A or in the pro-sphingolipid (e.g., LEKTCDWLPKPNMS (SEQ ID NO: 14), the underlined amino acids being naturally flanking amino acids of the DWLP (SEQ ID NO: 3) sequence in sphingolipid activating protein A. Thus, in some embodiments, the Psap peptide comprises the amino acid sequence DWLPKPNMS(SEQ ID NO:15)、CDWLPKPNM(SEQ ID NO:16)、TCDWLPKPN(SEQ ID NO:17)、KTCDWLPKP(SEQ ID NO:18)、EKTCDWLPK(SEQ ID NO:19)、LEKTCDWLP(SEQ ID NO:20) or amino acid substitution variants thereof, wherein the substitutions occur in CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3). Other examples of Psap peptides include, but are not limited to DWLPKPNMS(SEQ ID NO:21)、CDWLPKPNM(SEQ ID NO:22)、TCDWLPKPN(SEQ ID NO:23)、KTCDWLPKP(SEQ ID NO:24)、EKTCDWLPK(SEQ ID NO:25) and LEKTCDWLP (SEQ ID NO: 26). Other examples of Psap peptides include, but are not limited to DWLPKPNM(SEQ ID NO:27)、CDWLPKPN(SEQ ID NO:28)、TCDWLPKP(SEQ ID NO:29)、KTCDWLPK(SEQ ID NO:30)、EKTCDWLP(SEQ ID NO:31)、DWLPKPN(SEQ ID NO:32)、CDWLPKP(SEQ ID NO:33)、TCDWLPK(SEQ ID NO:34)、KTCDWLP(SEQ ID NO:35)、DWLPKP(SEQ ID NO:36)、CDWLPK(SEQ ID NO:1)、TCDWLP(SEQ ID NO:37)、DWLPK(SEQ ID NO:2)、CDWLP(SEQ ID NO:38) and DWLP (SEQ ID NO: 3).

It is also understood that the amino acids flanking CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3) are not necessarily the naturally flanking amino acids present in sphingolipid activating protein A or in the sphingolipid activating protein precursor, but may be any amino acid. Thus, the Psap peptide may comprise any number and identity of flanking amino acids. In some embodiments, the flanking amino acids may comprise an antibody or antibody Fc domain, serum transferrin or a portion thereof, albumin or transthyretin (see, e.g., g.m. subelanin, (2007), nature Biotechnology, 1411-141).

The Psap peptide may be synthesized using any method known in the art. Exemplary synthetic methods include, but are not limited to: recombinant synthesis, liquid phase synthesis, solid phase synthesis, chemical ligation (see, e.g., molecular Cloning: A Laboratory Manual, editions by J. Sambrook et al, third edition ,Cold Spring Harbor Laboratory Press,Cold Spring Harbor,New York,2001;Current Protocols in Molecular Biology,F.M.Ausubel, editions ,John Wiley&Sons,Inc.,New York;Schnolzer,M.A.,P.;Jones,A.;Alewood,D.;Kent,S.B.H.(2007)."In Situ Neutralization in Boc-chemistry Solid Phase Peptide Synthesis".Int.J.Peptide Res.Therap.13(1-2):31-44;Albericio,F.(2000).Solid-Phase Synthesis:A Practical Guide(1ed.).Boca Raton:CRC Press., page 848; and Nilsson BL,Soellner MB,Raines RT(2005)."Chemical Synthesis of Proteins".Annu.Rev.Biophys.Biomol.Struct.34:91-118;, and U.S. Pat. Nos. 4,749,742, 4,794,150, 5,552,471, 5,637,719, 6,001,966, 7,038,103, 7,094,943, 7,176,282, and 7,645,858, the entire contents of which are incorporated herein by reference).

In some embodiments, the Psap peptide may be modified, e.g., by oligomerization or polymerization (e.g., dimer, trimer, multimer, etc.), modification of amino acid residues or peptide backbones, crosslinking, cyclization, conjugation, pegylation (pegylation), glycosylation, acetylation, phosphorylation, fusion with additional heterologous amino acid sequences (e.g., antibody or antibody Fc domains, serum transferrin and portions thereof, albumin or transthyretin), or other modifications that substantially alter the stability, solubility, or other properties of the peptide while substantially maintaining or enhancing therapeutic activity. Conjugation may be, for example, conjugation with a polymer. Suitable polymers include, for example, polyethylene glycol (PEG), polyvinylpyrrolidone, polyvinyl alcohol, polyamino acids, divinyl ether maleic anhydride, N- (2-hydroxypropyl) -methacrylamide, dextran derivatives (including dextran sulfate), polypropylene glycol, polyoxyethylated polyols, heparin fragments, polysaccharides, cellulose and cellulose derivatives (including methylcellulose and carboxymethylcellulose), starch and starch derivatives, polyalkylene glycols and derivatives thereof, copolymers of polyalkylene glycols and derivatives thereof, polyvinyl ethyl ether and α, β -poly [ (2-hydroxyethyl) -DL-asparagine, and the like, or mixtures thereof. Conjugation may be performed through linkers (e.g., peptides or chemical linkers). Methods of modifying peptides are well known in the art (see, e.g., U.S. Pat. nos. No.:5,180,816、5,596,078、5,990,273、5,766,897、5,856,456、6,423,685、6,884,780、7,610,156、7,256,258、7,589,170 and 7,022,673 and PCT publication No. WO 2010/014616, the contents of which are incorporated herein by reference).

In some embodiments, the Psap peptide is a cyclic peptide. A cyclic peptide is a polypeptide chain whose amino-terminus and carboxyl-terminus are linked together by a peptide bond or other covalent bond to form a cyclic chain. In one embodiment, the peptide comprises amino and carboxy terminal cysteine amino acid residues. Cysteine facilitates S-S disulfide bond formation. In one embodiment, the peptide comprises an additional cysteine amino acid residue, wherein the cysteine amino acid residue is near the terminus, but not necessarily at the extreme terminus. In some embodiments, the cysteine amino acid residues are within five amino acid residues of the peptide terminus. Methods of designing and synthesizing cyclic peptides are well known in the art, for example, as described in U.S. Pat. Nos. 5,596,078, 5,990,273, 7,589,170 and U.S. patent application No. 20080287649.

In some embodiments, the Psap peptide is functionally modified to enhance stability. In some embodiments, the Psap peptide comprises an N-terminal acetyl group and/or a C-terminal amide group. In some embodiments, the Psap peptide comprises an N-terminal acetyl group and a C-terminal amide group. In some embodiments, the Psap peptide is Ac-dW 1P-amide or Ac-DWLP-amide (Ac=acetyl, lower case letters D and L refer to D-amino acids, SEQ ID NOS: 39 and 40, respectively). In some embodiments, chemical modifications of the Psap peptide include, but are not limited to, inclusion of alkyl, alkoxy, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl, alkenyl, alkynyl, cycloalkyl, amino, alkylamino, aminoalkyl, dialkylamino, aminodialkyl, halogen, heteroatom, carbocycle (carbocycle), carbocyclyl, carbocycle (carbocyclo), carbocycle (carbocyclic), aryl, aralkyl, aralkoxy, aryloxyalkyl, heterocycle (heterocycle), heterocyclyl, heterocyclic (heterocylic), heteroaryl, and/or aliphatic.

The Psap peptide also encompasses peptidomimetics (e.g., D-peptide, beta-peptide, and peptidomimetics (pepoids)). The peptide mimetic used may comprise the entire length of the Psap peptide, or only a portion of the Psap peptide. The peptidomimetics can include, for example, D amino acids, amide linkages for reduction of the peptide backbone, and non-peptide linkages linking side chains, pyrrolinones, and glycomimetics. The design and synthesis of glyco-backbone peptide mimetics (PEPTIDE MIMEIC) is described by Hirschmann et al (j. Med. Chem.,1996,36,2441-2448, which is incorporated herein by reference in its entirety). In addition, pyrrolinone-based peptide mimetics are also described (see, e.g., smith et al, J.Am. Chem. Soc.2000,122,11037-11038, which is incorporated herein by reference in its entirety). In some embodiments, the Psap peptide is in the form of a peptidomimetic (U.S. Pat. No.5,811,387; simon et al Proceedings of the National Academy of Sciences USA, (1992), 89 (20), 9367-9371). In some embodiments, the peptoid is poly-N-substituted glycine. In peptidomimetics, the side chain is attached to the nitrogen of the peptide backbone, rather than to the alpha carbon in the peptide. In some embodiments, the peptoid comprises nitroaromatic monomer units (Fowler et al, J Org chem.2009Feb 20;74 (4): 1440-9). In some embodiments, the peptidomimetics have an N substitution of an alpha chiral aromatic side chain at one or more residues (Gorske et al, J Am Chem Soc.2006Nov 8;128 (44): 14378-87). In some embodiments, the Psap peptide comprises a peptidomimetic region (i.e., comprising one or more side chains attached to the nitrogen of the peptide backbone) and a peptide region (i.e., comprising one or more side chains attached to the alpha carbon).

Psap amino acid substitutions

In some embodiments, the Psap peptide comprises an amino acid substitution variant of CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2), or DWLP (SEQ ID NO: 3), wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

c) Arginine (R) replaces lysine (K);

e) The D-isomer of tryptophan (W) replaces the L-isomer of tryptophan (W) and/or the D-isomer of proline (P) replaces the L-isomer of proline (P); or a combination thereof.

Conservative amino acid substitutions may be those in which one amino acid residue is replaced with an amino acid having a side chain of similar charge, size, polarity, hydrophobicity, or a combination thereof. Families of amino acid residues with side chains of similar charge have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, and histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine).

Conservative amino acid substitutions typically do not alter the overall structure of the peptide and/or the type of amino acid available to form van der Waals bonds with the binding partner. In some embodiments, the conservative substitution for leucine is valine. In some embodiments, the conservative substitution for leucine is valine or alanine.

In some embodiments, conservative substitutions or non-conservative substitutions of leucine are contemplated. In some embodiments, leucine is replaced with valine, glycine, or alanine. In some embodiments, leucine is replaced with glycine. In some embodiments, leucine is replaced with glycine or valine. In some embodiments, the amino acid substitution is a substitution of tyrosine (Y) for tryptophan (W).

Exemplary amino acid substitution variants include, but are not limited to DWAP (SEQ ID NO: 41), DYLPK (SEQ ID NO: 42), DWVPK (SEQ ID NO: 43), DWLPR (SEQ ID NO: 44), DWAPK (SEQ ID NO: 45), and DYLP (SEQ ID NO: 46).

Substitutions of non-standard amino acids are also contemplated herein. In some embodiments, leucine is replaced with a non-standard amino acid. In some embodiments, the nonstandard amino acid substitution of leucine has a size similar to leucine, valine, arginine, or glycine. Examples of non-standard amino acids include azidoalanine (azidoalanine), azidoglutaine (azidohomoalanine), azidofnorvaline, azidoglucine, homoallylglycine (homoallyglycine), homopropargylglycine (homoproparglycine), norvaline, norleucine, cis-crotylglycine (cis-crotyiglycine), trans-crotylglycine, 2-aminoheptanoic acid, 2-butynylglycine (butynyiglycine), allylglycine, 3- (1-naphthyl) alanine, 3- (2-naphthyl) alanine, p-ethynyl-phenylalanine, p-propynyl-oxy-phenylalanine, m-ethynyl-phenylalanine, 3- (6-chloroindolyl) alanine, 3- (6-bromoindolyl) alanine, 3- (5-bromoindolyl) alanine, azidoglycine, homopropargylglycine (homopropargylglycine), p-chlorophenylalanine, α -aminocaprylic acid, methylvaline, methylleucine or sarcosine. In some embodiments, leucine is replaced with a non-standard amino acid selected from methylvaline, methylleucine, or sarcosine. Non-standard amino acids and methods of their synthesis are well known in the art (see, e.g., U.S. patent publication nos. 2010-0249233, 2008-0214439, 2004-0053390, and 2004-0058415; pct publication No. WO 03/073238; and U.S. patent No.6,586,207, which are incorporated herein by reference in their entirety).

Amino acid substitutions can be made during chemical synthesis of the peptide by adding the desired substitution amino acid at the appropriate sequence during synthesis. Alternatively, molecular biological methods may be used. Non-conservative substitutions are contemplated to the extent that they substantially retain the activity of those peptides described herein.

As previously described, psap peptides containing CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3) with D-amino acid substitutions were also shown to have the desired therapeutic activity (see PCT application PCT/US2012/71424, published as PCT publication WO/2013/096868). Thus, amino acid substitution variants resulting from substitution of one or more D-amino acids for a similar L-amino acid are contemplated herein. In some embodiments, there are 1D-amino acid substitutions. In some embodiments, there are 2 or more D-amino acid substitutions. In some embodiments, there are 3, 4, or 5D-amino acid substitutions. In some embodiments, the D amino acid substitutions are uniformly spaced, e.g., every 4-6mer amino acid. In some embodiments, the D-amino acid substitution is for tryptophan (W) and/or proline (P). In some embodiments, the D-amino acid substitution is for aspartic acid (D) and/or leucine (L)). The L and D convention (convention) for amino acid configuration does not refer to the optical activity of the amino acid itself, but rather to the optical activity of the glyceraldehyde isomer from which the amino acid can be theoretically synthesized (D-glyceraldehyde is dextrorotatory, L-glyceraldehyde is levorotatory). Exemplary D amino acid substitutions include dW1P and DwLp (lowercase D and L refer to D-amino acids, respectively, SEQ ID NOs: 47 and 48).

Measurement

Some aspects of the disclosure relate to performing an assay to determine CD36 levels in a sample. CD36 levels may be measured using any assay known in the art (see, e.g., molecular Cloning: A Laboratory Manual, editions by j. Sambrook et al, third edition ,Cold Spring Harbor Laboratory Press,Cold Spring Harbor,New York,2001,Current Protocols in Molecular Biology,F.M.Ausubel, editions by John Wiley & Sons, inc., new York. Microarray technology is described in Microarray Methods and Protocols, r. Matson, CRC Press,2009 or Current Protocols in Molecular Biology, editions by f.m. ausubel et al, john Wiley & Sons, inc., new York). CD36 levels may be mRNA levels and/or protein levels. In some embodiments, the CD36 level is a protein level. Assays for detecting CD36 mRNA include, but are not limited to, northern blot analysis, RT-PCR, sequencing techniques, RNA in situ hybridization (hybridization to RNA molecules present in a sample using, for example, DNA or RNA probes), in situ RT-PCR (e.g., as described in Nuovo GJ et al Am J Surg Pathol 1993,17:683-90; kommioth P et al Pathol Res practice 1994, 190:1017-25), and oligonucleotide microarrays (e.g., by hybridization of polynucleotide sequences derived from a sample with oligonucleotides attached to a solid surface (e.g., a glass wafer) having addressable locations (addressable location), such as Affymetrix microarrays)SANTA CLARA, CA)). Methods for designing nucleic acid binding partners (e.g., probes) are well known in the art. In some embodiments, the nucleic acid binding partner binds to a portion of or the entire nucleic acid sequence of a CD36 nucleic acid sequence, provided herein are sequences that can be identified by the CD36 sequence.

Assays for detecting CD36 protein levels include, but are not limited to: immunoassays (also referred to herein as immune-based assays or immunobased assays, such as Western blot, immunohistochemistry and ELISA assays), mass spectrometry and multiplex bead-based assays. These assays for protein level detection are well known in the art. Binding partners for protein detection can be designed using methods known in the art and described herein. In some embodiments, a CD36 protein binding partner (e.g., an anti-CD 36 antibody) binds to a portion or the entire amino acid sequence of a CD36 protein amino acid sequence. Examples of other protein detection and quantification methods include multiplex immunoassays described, for example, in U.S. patent nos. 6939720 and 8148171 and published U.S. patent application No.2008/0255766, and protein microarrays described, for example, in published U.S. patent application No. 2009/0088329.

In some embodiments, the sample obtained from the subject is a tumor biopsy (biopsy), and the assay for detecting CD36 protein levels is an immune-based assay performed on the tumor biopsy.

Any suitable binding partner for CD36 is contemplated for use in detecting CD36 levels. In some embodiments, the binding partner is any molecule that specifically binds to CD36 protein. By "specifically bind to CD36 protein" as used herein is meant that the molecule is more likely to bind to a portion or whole of CD36 protein than to a portion or whole of non-CD 36 protein. In some embodiments, the binding partner is an antibody or antigen-binding fragment thereof, e.g., fab, F (ab) 2, fv, single chain antibody, fab and sFab fragments, F (ab') 2, fd fragment, scFv, or dAb fragment. Methods for producing antibodies and antigen binding fragments thereof are well known in the art (see, e.g., sambrook et al, "Molecular Cloning: A Laboratory Manual" (second edition ),Cold Spring Harbor Laboratory Press(1989);Lewin,"Genes IV",Oxford University Press,New York,(1990), and Roitt et al, "Immunology" (second edition), gower Medical Publishing, london, new York (1989), WO2006/040153, WO2006/122786 and WO 2003/002609). Binding partners also include other peptide molecules and aptamers that specifically bind to CD 36. Methods for producing peptide molecules and aptamers are well known in the art (see, e.g., published U.S. patent application No.2009/0075834, U.S. patent nos. 7435542, 7807351 and 7239742).

Commercially available CD36 antibodies include, for example, N-15, SM phi, L-17, ME542, H300, 185-1G2, and V-19 from Santa Cruz Biotechnology (catalog numbers sc-5522, sc-7309, sc-13572, sc-5523, sc-9154, sc-2172, and sc-7641, respectively), JC63.1 from Abcam, FA6-152, and anti-CD 36 (catalog numbers ab23680, ab17044, and ab78054, respectively).

In some embodiments, the binding partner is any molecule that specifically binds to CD36 mRNA. As used herein, "specifically binds to CD36 mRNA" means that the molecule is more likely to bind to a portion or whole of CD36mRNA (e.g., by complementary base pairing) than to a portion or whole of non-CD 36mRNA or other non-CD 36 nucleic acid. In some embodiments, the binding partner that specifically binds to CD36mRNA is a nucleic acid, e.g., a probe. The nucleotide and amino acid sequences of CD36 provided herein can be used to design binding partners. In some embodiments, the CD36 binding partner may comprise a detectable label, such as an enzymatically active group, a fluorescent molecule, a chromophore, a luminescent molecule, a specifically-bindable ligand, or a radioisotope. In some embodiments, a second binding partner, such as a secondary antibody, specific for the CD36 binding partner is also contemplated.

Sample of

Some aspects of the disclosure relate to determining CD36 levels in a sample obtained from a subject. In some embodiments, the sample obtained from the subject is a tumor sample. Tumor samples as used herein may include, for example, tumor cells, tumor cell populations, tumor fragments (e.g., biopsies), or whole tumors. In some embodiments, the tumor sample is a tumor biopsy. In some embodiments, the tumor sample comprises circulating tumor cells. In some embodiments, the tumor sample comprises ascites fluid (ascite). In some embodiments, the tumor sample comprises pleural fluid. The tumor sample may comprise non-tumor cells or non-tumor tissue (e.g., a biopsy comprising normal tissue surrounding tumor fragments). In some embodiments, the sample may be a tissue or fluid sample obtained from a subject. Examples of fluid samples are blood, plasma, serum and urine.

Object(s)

Some aspects of the disclosure relate to a subject, e.g., a human subject, suffering from cancer. Any type of cancer is contemplated herein, including, but not limited to, leukemia, lymphoma, myeloma, carcinoma, metastatic carcinoma, sarcoma, adenoma, cancers of the nervous system, and cancers of the genitourinary system. Exemplary cancer types include adult and pediatric acute lymphoblastic leukemia, acute myelogenous leukemia, adrenocortical carcinoma, AIDS-related cancers, anal cancers, appendicular cancers, astrocytomas, basal cell carcinomas, cholangiocarcinomas, bladder cancers, bone cancers, osteosarcomas, fibroblastic tumors, brain cancers, brain stem gliomas, cerebellar astrocytomas, malignant gliomas, ependymomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, hypothalamic gliomas, breast cancers, male breast cancers, bronchial adenomas, burkitt lymphomas, carcinoid tumors, cancers of unknown origin, central nervous system lymphomas, cerebellar astrocytomas, malignant gliomas, cervical cancer, childhood cancers, chronic lymphocytic leukemia, chronic myelogenous leukemia, chronic myeloproliferative disorders, colorectal cancer skin T cell lymphoma, endometrial carcinoma, ependymoma, esophageal carcinoma, ewing family tumors (EWING FAMILY tumor), extracranial germ cell tumors, extragonadal germ cell tumors, extrahepatic duct carcinoma, intraocular melanoma, retinoblastoma, gallbladder carcinoma, gastric cancer, gastrointestinal stromal tumors, extracranial germ cell tumors, extragonadal germ cell tumors, ovarian germ cell tumors, gestational trophoblastoma (gestational trophoblastic tumor), glioma, hairy cell leukemia, head and neck cancer, hepatocellular carcinoma, hodgkin's lymphoma, non-Hodgkin's lymphoma, hypopharyngeal carcinoma, hypothalamic and optic pathway glioma, intraocular melanoma, islet cell tumors, kaposi's sarcoma, renal carcinoma, renal cell carcinoma, laryngeal carcinoma, lip and oral cavity carcinoma, small cell lung carcinoma, non-small cell lung carcinoma, primary central nervous system lymphoma, vardenstrual macroglobulinemia, malignant fibrous histiocytoma, medulloblastoma, melanoma, merkel cell carcinoma, malignant mesothelioma, squamous neck carcinoma, multiple endocrine neoplasia syndrome, multiple myeloma, mycosis fungoides (mycosis fungoides), myelodysplastic syndrome, myeloproliferative disorders, chronic myeloproliferative disorders, nasal and paranasal sinus cancer, nasopharyngeal carcinoma, neuroblastoma, oropharyngeal carcinoma, ovarian carcinoma, pancreatic carcinoma, parathyroid carcinoma, penile carcinoma, pharyngeal carcinoma, pheochromocytoma, pineal tumor and supratentorial primitive neuroectodermal tumor, pituitary carcinoma, plasmacytoma, pleural pneumoblastoma, prostate carcinoma, rectal carcinoma, rhabdomyosarcoma, salivary gland carcinoma, soft tissue sarcoma, uterine sarcoma, sai-Rizel syndrome, non-melanoma skin carcinoma, small intestine carcinoma, squamous cell carcinoma, squamous neck carcinoma, supratentorial primitive neuroectodermal carcinoma, testicular carcinoma, laryngeal carcinoma, thymoma and thymus carcinoma, transitional cell carcinoma, thyroid carcinoma, vulval carcinoma, uterine sarcoma, cervical carcinoma, or Wills's tumor.

In some embodiments, the cancer is prostate cancer, breast cancer, ovarian cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma. In some embodiments, the cancer is prostate cancer, breast cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma. In some embodiments, the cancer is pancreatic cancer, ovarian cancer, breast cancer, prostate cancer, melanoma, or lung cancer.

Control and control level

Further aspects of the disclosure relate to comparing CD36 levels in a sample to control levels. In some embodiments, the control level is a level of CD36 in a cell, tissue or fluid obtained from a healthy subject or population of healthy subjects. Healthy subjects, as used herein, are subjects that are apparently free of disease (e.g., cancer) and have no history of disease.

In some embodiments, the control level is determined from a sample obtained from a subject having cancer. Thus, in some embodiments, the control level is obtained from the same subject from which the sample was obtained. In some embodiments, the control level is a CD36 level in a non-cancerous cell or tissue obtained from a subject having cancer.

In some embodiments, the control level is an undetectable CD36 level or a CD36 level that is lower than the background/noise level obtained using standard detection methods (e.g., western blot or immunohistochemistry).

The present disclosure also relates to comparing CD36 levels in a sample obtained from a subject to a predetermined level or value (e.g., a control level) that does not require each measurement. The predetermined level or value may take a variety of forms. Which may be a single cut-off value, such as a median or average. It may be established based on a comparative group, for example, where one determined group is known to be non-responsive to the Psap peptide treatment and another determined group is known to be responsive to the Psap peptide treatment. It may be a range, for example, where the test population is equally (or unequally) divided into groups, such as not responsive to, slightly responsive to, and highly responsive to the Psap peptide treatment, or divided into quadrants (quadrants), the lowest quadrant being the subject that does not respond to the Psap peptide treatment and the highest quadrant being the subject that has the highest response to the Psap peptide treatment.

The predetermined value may depend on the particular population selected. For example, a significantly healthy population (no detectable cancer and no prior history of cancer) will have a different "normal" range of CD36 compared to a population in which the member has cancer but is known to not respond to treatment with the Psap peptide. Thus, the predetermined value selected may take into account the category into which the patient falls. One of ordinary skill in the art can select the appropriate range and category by only routine experimentation.

Examples

Example 1

Method of

Cell lines and primary cells

Cell line PC3 was previously described (Kang et al PNAS.2009; 106:12115-20). PC3 cells were cultured in RPMI with 10% fbs. Human breast cancer cell lines MDA-MB-231 and MCF-7 (Ryu et al PLoS one,6,2011) were previously described. Murine Lewis lung cancer cell line LLC (supplied by Lea Eisenbach, wiesmann Institute of Science, rehoot, israel) stably expressing RFP and firefly luciferase was cultured in DMEM supplemented with 10% fetal bovine serum (Gupta GP,Massague J.Cancer metastasis:building a framework.Cell.2006;127:679-95;Gao D,Nolan DJ,Mellick AS,Bambino K,McDonnell K,Mittal V.Endothelial progenitor cells control the angiogenic switch in mouse lung metastasis.Science.2008;319:195-8; and Joyce JA, polard jw. Micro visual regulation of metatasis. Nat Rev cancer.2009; 9:239-52). B16 melanoma cells, LNCaP prostate cancer cells, asPc1 pancreatic cancer cells, and ID8 ovarian cancer cells were previously described (Overwijk WW et al B16 as a mouse model for human melanoma.Curr Protoc Immunol.2001,May;Chapter 20:Unit 20.1;Horoszewicz JS,Leong SS,Kawinski E et al LNCaP model of human prostatic cancer Res.1983, apr;43 (4): 1809-18.; chen WH et al Human pancreatic adenocarcinoma:in vitro and in vivo morphology of a new tumor line established from ascites.In Vitro 18:24-34,1982; and Roby KF et al Development of a syngeneic mouse model for events related to ovarian cancer.Carcinogenesis.2000,21:585-591). primary ovarian cancer cells were derived from ascites in ovarian cancer patients).

Western blot analysis

Cells were homogenized in lysis buffer (BioRad) containing protease inhibitor (Roche APPLIED SCIENCE). Samples were boiled in 1 XSDS sampling buffer and loaded onto a 4-20% gradient Bis-Tris NuPAGE gel (Invitrogen). Western blots were performed using antibodies specific for CD36 (AbCam, ab 78054) or beta-actin (Sigma-Aldrich).

In vitro cell proliferation assay

Cell proliferation was measured using an MTT (3- {4, 5-dimethylthiazol-2-yl } -2, 5-diphenyltetrazolium bromide, sigma-Aldrich) assay. Cells were inoculated into 50 μl of growth medium in 96 well plates and allowed to attach overnight. Then 50. Mu.L of growth medium and two-fold concentration of treatment reagent were added. After each treatment time point, 10 μl of 5% mtt solution (buffered in PBS) was added to each well. Plates were incubated at 37℃for an additional 4 hours to allow metabolic conversion of MTT to formazan in the cell mitochondria(Formazan) crystals. The methyl/>, was achieved by adding 100 μl of 10% sodium dodecyl sulfate in 50% N-N-dimethylformamide to the wells of each microplateThe crystals eventually dissolve. Measurement of 550nm and 680nm (corresponding to methyl/>, respectively) using colorimetric microplate readerSalt and reference wavelength). Wells containing complete medium alone were used as controls. Each experiment was performed in duplicate, with 6 replicates for each drug concentration.

Results

It is hypothesized that Tsp-1 upregulated by the Psap peptide may act directly on cancer cells, rather than merely through an indirect anti-angiogenic mechanism. To test this hypothesis, LLC cells were treated with recombinant Tsp-1 or DWLPK (SEQ ID NO: 2) Psap peptide, and cell proliferation was measured using an MTT assay. Tsp-1 was found to reduce cell proliferation, whereas the Psap peptide did not affect cell proliferation (fig. 1A). This supports the hypothesis that Tsp-1 can act directly on cancer cells, as the assay is performed in vitro in the absence of any blood vessels. These results also indicate that the Psap peptide alone does not exhibit an effect on cancer cell proliferation, supporting the hypothesis that Psap peptides can indirectly treat cancer by upregulating Tsp-1. LLC cells are shown to express CD36 (receptor for Tsp-1), suggesting that Tsp-1 may act directly on cancer cells via CD36 (FIG. 1B).

CD36 levels were measured in other cell lines to see if additional cancer types also expressed CD36. CD36 levels in breast cancer (MDA-231, MCF-7), ovarian cancer (ID 8), melanoma (B16), prostate cancer (PC 3 and LNCaP), and lung cancer (LLC) cell lines were measured by western blot analysis. CD36 protein was found to be detectable in all of the tested cell lines, with particularly high CD36 levels being detectable in MDA-231, MCF-7, PC3 and LLC cell lines (FIG. 2). MDA-231, ID8, B16, PC3, and LLC cells have been previously shown to respond to in vivo Psap peptide treatment.

The pancreatic cell line AsPc1 was also examined and found to express CD36.

CD36 levels were also measured in primary ovarian cancer cells derived from patients with ascites. CD36 protein was detectable in all primary ovarian cancer cells tested (fig. 3).

Example 2

Method of

Mice and cell lines

All animal work was performed according to the Institutional ANIMAL CARE AND Use Committee approved protocol. Wild-type C57BL/6J and GFP transgenic C57BL/6-Tg (ACTB-EGFP) 1Osb/J were obtained from The Jackson Laboratory (Bar Harbor, maine). CB-17SCID mice were obtained from CHARLES RIVER (Wilmington, mass.).

Cell lines PC3 and PC3M-LN4 were previously described (14). Human breast cancer cell lines MDA-MB-231 and MDA-MB-LM2 (Ryu et al PLoS one,6,2011) were previously described. Murine Lewis lung carcinoma cell line LLCs/D122 (supplied by Lea Eisenbach, wiesmann Institute of Science, rehovot, israel) stably expressing RFP and firefly luciferases was cultured in DMEM supplemented with 10% fetal bovine serum (Gupta GP,Massague J.Cancer metastasis:building a framework.Cell.2006;127:679-95;Gao D,Nolan DJ,Mellick AS,Bambino K,McDonnell K,Mittal V.Endothelial progenitor cells control the angiogenic switch in mouse lung metastasis.Science.2008;319:195-8; and Joyce JA, polarod JW. Micro visual regulation of metatasis. Nat Rev cancer 2009; 9:239-52).

Tissue microarray and immunohistochemistry

Archive samples (prostatectomy samples or biopsies of metastases) were taken from the file DEPARTMENT OF PATHOLOGY, the Gade Institute, haukeland University Hospital. Formalin-fixed prostatectomy specimens were paraffin-embedded and studied in 5 mm-spaced whole-block procedures. In each case, three tissue cores (0.6 mm diameter) were selected from the highest tumor grade region to construct a Tissue Microarray (TMA).

Thin paraffin sections (5 μm) from TMA paraffin blocks were deparaffinized with xylene/ethanol and then subjected to heat-induced microwave epitope retrieval in citrate buffer (pH 6.0) for 20min, incubated with CD36 antibody for 60 min at room temperature. Immunostaining was performed on a Dako autostainer using the EnVision chain polymer method (Dako Cytomation, copenhagen, denmark) as the detection system. Antigen localization was achieved with hematoxylin counterstaining using DAB diaminobenzidine peroxidase reaction.

Immunostaining was estimated semi-quantitatively, and a Staining Index (SI) obtained as the product of staining intensity (0-3) and the proportion of immune positive tumor cells (< 10% = 1,10-50% = 2, >50% = 3) was calculated. The staining index (range 0-9) is a classification scale in which some variation in each category is expected.

Knock down of CD36 in tumor cells

The use of a retroviral or lentiviral vector encoding a CD 36-targeting miRNA or shRNA reduces CD36 levels in cancer cell lines. Knockdown efficiency was tested using qPCR analysis. Total RNA extraction was performed using PicoPure RNA extraction kit (Arctus) according to the manufacturer's protocol. RNA was converted to cDNA using qScript ^TM cDNA supermix (Quanta biosciences). qPCR was performed with primers and iQTM SYBER GREEN MASTER mix (Biorad, hercule, calif.). The following standard protocol was performed on a BioRad CFX96REAL TIME SYSTEM (BioRad) coupled with Bio-Rad-CFX Manager software: initial denaturation was performed for 10 min at 95 ℃,10 sec, 60 ℃,30 sec and 72 ℃, 40 cycles, followed by final extension at 72 ℃ for 5min, and dissolution profile analysis was performed. The relative abundance of each transcript compared to the control was calculated using the delta-Ct method.

In vitro cell proliferation assay

Cell proliferation was measured using an MTT (3- {4, 5-dimethylthiazol-2-yl } -2, 5-diphenyltetrazolium bromide, sigma-Aldrich) assay. Cells were inoculated into 50 μl of growth medium in 96 well plates and allowed to attach overnight. Then 50. Mu.L of growth medium and two-fold concentration of treatment reagent were added. After each treatment time point, 10 μl of 5% mtt solution (buffered in PBS) was added to each well. Plates were incubated at 37℃for an additional 4 hours to allow metabolic conversion of MTT to formazan in the cell mitochondriaAnd (5) a crystal. The methyl/>, was achieved by adding 100 μl of 10% sodium dodecyl sulfate in 50% N-N-dimethylformamide to the wells of each microplateThe crystals eventually dissolve. Measurement of 550nm and 680nm (corresponding to methyl/>, respectively) using colorimetric microplate readerSalt and reference wavelength). Wells containing complete medium alone were used as controls. Each experiment was performed in duplicate, with 6 replicates for each drug concentration.

Metastasis determination, biological optical imaging and analysis

For experimental metastases, 7 week old C57BL/6 mice were injected with 1X 10 ⁵ luciferase-labeled LLC cells via the tail vein. For in situ breast cancer cell injection, 5X 10 ⁶ MDA-MB-231 or its metastatic variant MDA-MB-LM2 cells were injected into the CB-17SCID mouse fat pad at a volume of 0.1 ml. Tumor growth and lung metastases (after excision of the primary lung tumor) were monitored weekly by live animal bioluminescence imaging (Xenogen). For in situ prostate cancer cell injection, 2 x 10 ⁶ live LN4 or cells were injected into the prostate of mice.

For in vivo determination of metastatic burden, mice were anesthetized and injected intraperitoneally with 75mg/kg of D-luciferin (100 μl, 30mg/mL in PBS). Growth of metastases over time was monitored in supine mice 5 min after D-luciferin injection using bioluminescence with a Xenogen IVIS system coupled with LIVING IMAGE acquisition and analysis software (Xenogen). For the BLI plot, photon flux was calculated for each mouse by using the same circular region of interest surrounding the mouse chest.

Administration of Psap peptides

Mice 8 weeks old were treated with Psap peptide (e.g., DWLPK (SEQ ID NO: 2), DWLP (SEQ ID NO: 3), or modified version thereof) diluted in PBS at a dose of 30 mg/kg/day for 2 weeks by intraperitoneal injection.

Results

CD36 levels are measured in tissue samples from human subjects with cancer.

CD36 levels in cancer cell lines were knocked down and mice were injected with these cell lines with reduced CD 36. The mice were then administered the Psap peptide. Tumor growth and metastatic burden were monitored. It is expected that knocking down CD36 in cancer cells will reduce the anticancer activity of the Psap peptide in vivo.

Example 3

Method of

The method used in example 3 is the same as that used in examples 1 and 2, unless otherwise specified. Cell lines tested for CD36 expression are pancreatic cancer (AsPC 1), ovarian cancer (DF-14 and ID-8), breast cancer (MDA-MB 231 and LM 2), prostate cancer (PC 3, PC3-M-LN4, LN-CAP and LN-CAP-LN 3), melanoma ((B16-B16) and lung cancer (LLC) cell lines.

Ovarian cancer cells expressing CD36 were treated with control or thrombospondin (Tsp-1, 100ng, 500ng or 1000 ng) and the percentage of surviving cells was measured at 0 hours or 48 hours.

For the ovarian cancer mouse model, 1 million luciferase-expressing ovarian cancer cells were injected intraperitoneally. Treatment with cisplatin (4 mg/kg QOD), psap peptide dWlP (SEQ ID NO:47,40mg/kg QD), a combination of cisplatin and Psap peptide, or PBS QD was started 17 days later. Luciferase intensity was measured over days starting at about 17 days and measured over time.

For the pancreatic cancer mouse model, 1×10 ⁶ AsPc1 human pancreatic cells were injected into the pancreas of SCID mice. Mice were treated with control or with Psap peptide dWlP (SEQ ID NO:47,20 mg/kg/day or 40/mg/kg/day). Treatment was started on day 25 and continued daily for 21 days. Mice were then euthanized and primary tumor masses were measured. It was also measured whether ascites was present.

For the melanoma mouse model, B16-B16 cells were injected into mice. Mice were treated with psap peptide dWlP (SEQ ID NO:47,10 or 40/mg/kg) or controls. Tumor volumes were measured over time until about 20-25 days after cell injection.

Results

CD36 expression was tested for a number of cancer cell lines. CD36 protein was found to be detectable in all cell lines tested, with particularly high CD36 levels being detectable in the AsPC1, DF-14, MDA-MB231 and PC3 cell lines (FIG. 5).

Ovarian cells expressing CD36 have been shown to be sensitive to Tsp-1 mediated cell killing in a dose-dependent manner (fig. 6).

Two "high" CD36 cell lines (ovarian cancer cells and AsPC pancreatic cancer cells) and one "low" CD36 cell line (B16-B6 cancer cells) were injected into mice to study the effect of psap peptides on tumor growth and metastasis. The "high" CD36 cancer model was found to regress in response to Psap peptide treatment (fig. 5 and 7). Ovarian cancer models also showed regression of metastatic disease (fig. 5). Pancreatic cancer models also showed inhibition of metastasis, as only 1 out of 19 mice treated with psap peptide formed ascites, while 4 out of 10 mice treated with control formed ascites. In the "low" CD36 melanoma model, psap peptide treatment was found to inhibit primary tumor growth, but did not cause tumor regression (fig. 8). These results indicate that "high" CD36 cancers are more likely to respond strongly to Psap peptide treatment (e.g., regression of primary tumor and/or metastasis), while "low" CD36 cancers are more likely to have weaker responses (e.g., inhibition of primary tumor rather than regression).

Without further elaboration, it is believed that one skilled in the art can, based on the preceding description, utilize the present disclosure to its fullest extent. Accordingly, the specific embodiments should be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. All publications cited herein are incorporated by reference for the purposes or subjects described herein.

The term "at least one" as used herein in the specification and claims should be understood to mean "at least one" unless explicitly indicated to the contrary.

From the foregoing description, one skilled in the art can readily ascertain the essential characteristics of this disclosure, and without departing from the spirit and scope thereof, can make various changes and modifications of the disclosure to adapt it to various usages and conditions. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A method for assessing responsiveness of a subject to treatment with a Psap peptide, the method comprising:

Determining the level of CD36 in a sample obtained from a subject having cancer, wherein an elevated level of CD36 in the sample as compared to a control level indicates that the subject is or is likely to be responsive to treatment with a Psap peptide.

2. The method of claim 1, wherein the level of CD36 in the sample is determined by performing an assay.

3. The method of claim 1 or 2, wherein the method further comprises:

Identifying a subject having an elevated level of CD36 in the sample as responsive or likely responsive to treatment with the Psap peptide as compared to a control level.

4. A method according to claim 3, wherein the method further comprises:

Administering an effective amount of a Psap peptide to the subject identified as responsive or likely responsive to treatment with the Psap peptide to treat the cancer.

5. A method for treating a subject having cancer, the method comprising:

administering an effective amount of a Psap peptide to a subject having cancer characterized by elevated CD36 levels in a sample as compared to a control level to treat the cancer.

6. A method for treating a subject having cancer, the method comprising:

(a) Selecting a subject with cancer based on the known subject having an elevated level of CD36 in the sample as compared to a control level, and

(B) Because the subject has an elevated level of CD36 in the sample as compared to a control level, an effective amount of the Psap peptide is administered to the subject.

7. The method of any one of claims 1 to 6, wherein the control level is a CD36 level in a non-cancerous cell or tissue obtained from the subject having cancer.

8. The method of any one of claims 1 to 6, wherein the control level is a CD36 level in a cell or tissue obtained from a healthy subject or population of healthy subjects.

9. The method of any one of claims 1 to 6, wherein the control level is a predetermined level.

10. The method of any one of claims 1 to 9, wherein the CD36 level is a CD36 protein level.

11. The method of any one of claims 1 to 10, wherein the cancer is prostate cancer, breast cancer, ovarian cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma.

12. The method according to any one of claims 1 to 11, wherein the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3), or an amino acid substitution variant thereof, wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

c) Arginine (R) replaces lysine (K);

13. The method of claim 12, wherein the Psap peptide is 50 amino acids or less in length.

14. The method of claim 13, wherein the Psap peptide is 30 amino acids or less in length.

15. The method of claim 14, wherein the Psap peptide is 15 amino acids or less in length.

16. The method of claim 15, wherein the Psap peptide is 6 amino acids or less in length.

17. The method of claim 12, wherein the Psap peptide is a cyclic peptide.

18. The method of any one of claims 12 to 17, wherein the similarly sized non-standard amino acid is methylvaline, methylleucine or sarcosine.

19. A composition for treating a subject having cancer characterized by elevated CD36 levels in a sample as compared to a control level, the composition comprising a Psap peptide.

20. Use of a composition comprising a Psap peptide in the manufacture of a medicament for treating a subject having cancer characterized by an elevated level of CD36 in a sample as compared to a control level.

21. The composition or use of claim 19 or 20, wherein the control level is a CD36 level in a non-cancerous cell or tissue obtained from the subject having cancer.

22. The composition or use of claim 19 or 20, wherein the control level is a CD36 level in a cell or tissue obtained from a healthy subject or population of healthy subjects.

23. The composition or use of claim 19 or 20, wherein the control level is a predetermined level.

24. The composition or use of any one of claims 19 to 23, wherein the CD36 level is a CD36 protein level.

25. The composition or use of any one of claims 19 to 24, wherein the cancer is prostate cancer, breast cancer, ovarian cancer, lung cancer, leukemia, pancreatic cancer, glioblastoma multiforme, astrocytoma, or melanoma.

26. The composition or use of any one of claims 19 to 25, wherein the Psap peptide comprises the amino acid sequence CDWLPK (SEQ ID NO: 1), DWLPK (SEQ ID NO: 2) or DWLP (SEQ ID NO: 3), or an amino acid substitution variant thereof, wherein the amino acid substitution is:

a) Tyrosine (Y) replaces tryptophan (W);

c) Arginine (R) replaces lysine (K);

27. The composition or use of claim 26, wherein the Psap peptide is 50 amino acids or less in length.

28. The composition or use of claim 27, wherein the Psap peptide is 30 amino acids or less in length.

29. The composition or use of claim 28, wherein the Psap peptide is 15 amino acids or less in length.

30. The composition or use of claim 29, wherein the Psap peptide is 6 amino acids or less in length.

31. The composition or use of claim 26, wherein the Psap peptide is a cyclic peptide.

32. The composition or use of any one of claims 26 to 31, wherein the similarly sized non-standard amino acid is methylvaline, methylleucine or sarcosine.

33. The method, use or composition of any one of claims 1 to 32, wherein the sample is a tumor sample.